Apparatus for burning liquid fuels



Jun 1 4, 1938. M. A. POWERS ET AL 2,120,626

APPARATUS FOR BURNING LIQUID FUELS Filed Sept. 28, 1934 3 Sheets-Sheet 1 fill/r00 A. Power:

Joli/2 All I760 m M 1 W W June 14, 1938. M. A. PowER's ET AL APPARATUS FOR BURNING LIQUID FUELS Filed Sept. 28, 1934 3 Sh'eetS-Shet 2 June 14, 1.9.38. M, A. owERs r AL 2,120,626

APPARATUS FOR BURNING LIQUID FUELS Fil-ed Sept. 28, 1934 3 Sheets-Sheet 3 Y QM ff/WM;

patented tam t, rest estates arrnna'rus son assume from rears Milton A. Powers and John A. Wilson, Detroit, Mich, assignors, by mesne assignments, to The 'iimlren-llletroit Axle Company, a corporation oi Ohio Application September 28, 1934, Serial No. 745,978 '5 Claims. (cl. ISt-dii) t 'itt ttt This invention relates to pressure-type liquid fuel burners, and more specifically to what are commonly known as gun-type burners.

Devices of this nature are provided with means for supplying liquid fuel under pressure to a nozzle or spray jet where it is ejected in a fine spray, ordinarily of conical shape. There is also a provision for supplying a controlledquantity of air to mix with the spray and a means for igniting the combustible mixture thus formed. The velocity of the air blows the ignited mixture into a combustion chamber into which the nose of the burner projects. The combustion chamber is ordinarily the lower interior portion of a conventional furnace and when its walls are heated by the flame produced by the burner, heat is transferred to the heating medi whether it be water or air.

Prior devices of this nature have been extremely complex in structure-numerous pipes and wires being exposed on the exterior. Thus anyone may tamper with them, and also as the burner is ordinarily placed on, the floor these pipes and wires and other parts may be tripped over, and often pulled out of engagement. Further, these exposed pipes and wires materially detract from the appearance of the device, and although beauty is not a prime requisite of an oil burner, this factor is of importance as such burners are placed outside of the furnace and are exposed to view all of the time.

The efficiency of prior burners of this class has not been very great due to the fact that the combustible mixture is discharged through the nose of the burner in a straight line, impact with a wall of the combustion chamber opposite the burner nose being relied upon to distribute the combustible mixture throughout the combustion chamber. Due to this method of flame distribution, carbon is collected on. what might be termed the impact wall, which partially insulates the heat absorbing surface from the flame and produces a resultant decrease in efficiency. Also, thorough distribution of the flame throughout the combustion chamber is not obtained.

In gun-type burners heretofore proposed, it has i not been possible to obtain even fair operation in certain installations, by reason of the burner parts not being adjusted to properly take care of the operating factors of the installation involved.

It is accordingly a primary object of the present invention to devise a novel gun-type burner that presents a minimum of exposed pipes and wires, and is of relatively light Weight.

It is another important objectof this invention to devise a liquid fuel burner having all of the parts which affect combustion efficiency, mounted for adjustment so that all of the peculiarities of any installation may be compensated for and the efliciency of the burner raised to a maximum.

It is a further object of this invention to devise a gun-type burner which imparts a swirling motion to the combustible mixture and flame, whereby complete flame distribution is obtained.

A further object is to devise a gun-type burner having an oil spraying means and an air swirling means that may be adjusted with respect to each other so as to obtain ideal combustion conditions.

A further object is to provide a gun-type burner wherein the ignition means may be adjusted with respect to the oil-spraying means, in order. to

permit of several types of spray nozzles being used. I 1

A further object is to provide a gun-type burner having an oilspraying means and an ignition means which may be jointly adjusted with respect to an air-swirling means.

These and further objects will be evident upon a study of the following detailed description in connection with the annexed drawings, and from the appended claims.

In the drawings:

Figure 1 is a plan view of a burner embodying our invention, with parts thereof broken away to more clearly illustrate the construction.

Figure 2 is a side elcyational view of the burner shown in Figure 1, with a part of the conduit broken away.

Figure 3 is a side sectional viewtakensubstantially on the line 3-3 of Figure 1, and

Figure 4 is a vertical sectional view taken substantially on the line l--i of Figure 2.

With continued reference to the drawings wherein like reference characters have been employed to designate like parts throughout the several views, the burner consists essentially of portion 3 in which fan B revolves. 0n one side of circular portion 3 is a flat surface to which is bolted motor A which may be of any suitable type. on the opposite side of the circular portion is a cylindrical extension 5, having a series of air intake apertures "i formed therein. Placed around cylindrical portion 5 is a cylindrical stamping 9, termed an air shutter, having a series of apertures H which mate with apertures l. The extremities of stamping 9 are provided with ears l3 which have aligned apertures therethrough for the insertion of a clamping screw and nut assembly i5. The air shutter 9 is adapted to be rocked a slight angular distance on cured thereto by cap screws l1. Device C may be of any suitable form and supplies oilto the spray nozzle E under a predetermined pressure.

On the underside of housing I are three bosses l8, spaced in triangular fashion with respect to the housingone being placed centrally under conduit D and the other two being adjacent the rear portion of housing I and equally spaced outwardly with respect to the longitudinal axis of the burner. Bosses l8 are threadedly apertured for the insertion of studs l9. Three pads 20 are also provided with threaded apertures which are threaded onto studs l9. The burner is suitably positioned with respect to the surface on which it rests by screwing'feet 20 upwardly or downwardlyas the case may be. Lock nuts 2|, on studs 19, are then screwed down against the upper surfaces of feet 20, thus permanently retaining the correct adjusted position.

Shaft 22 of motor A projects into housing 3 and drives air-blower or fan B. The fan may assume any desired form but it is substantially cup-shaped and comprises a circular series of blades 23 bent inwardly from the outer periphery or wall portion of the cup, and a hub 25 provided centrally in the flat or bottom portion of the cup. A set screw 21 is threadedly inserted through the hub and against shaft 22- thereby providing a driving connection between the fan andthe motor.

Oil pump C has a shaft 3| extending into. cylindricalportion 5 of housing l. Motor shaft 22 and oil pump shaft 3| terminate in close abutting relationship and are connected together by means of a flexible coupling 33. Coupling 33 takes care of and absorbs any misalignment between the two shafts, so that undue stresses are not transmitted to their respective mechanisms. It is accordingly seen that the motor constitutes a single 7 driving means for operating the air and oil supplying means.

It is to be understood that no novelty is claimed for the motor A, or oil pump C per se, as any conventional motor or pump which has the desired characteristics and dimensions may be used. Suffice it to say that the oil pump C is provided with an inlet line 31 which connects with a suitable oil reservoir (not shown) and an oil outlet line 39. Suitable mechanism is provided within the oil pump for straining the oil and for automatically regulating the pressure in the oil supplied to oil outlet line 39.

It is to be noted that the pipe line constituting oil outlet 39 is the only exposed pipe line interconnecting burner parts, and that it is out of the way as it projects downwardly and then turns inwardly so that it lays along the burner housing. Pipe line 39 enters'the burner housing I through a slot 4| provided therefor in inspection cover 43 which is secured to conduit D. Cover 43 is made of thin sheet metal and is shaped to flt the contour of conduit D and two screws 45 are provided to clamp the cover in place. On theinterior of conduit D, pipe 39 is connected at 41 to'pipe 49 which has screwed on its outer end an oil nozzle or spray jet E, and is suitably supported in conduit D by means yet to be described.

Immediately in front of circular portion 3 of housing I and removably secured to the top portion of conduit D is transformer G. Thetransformer is'of conventional type, having a 110 volt primary and a 10,000 volt secondary. The primary leads 55 of the transformer extend within housing I to a connector box H. The motor is provided with leads 51 which likewise extend within the housing to connector box H. Connector box H is provided with three binding posts 59 for the attachment of the wires which connect with the burner control mechanism (not shown). A pair of high tension leads 6| connect the secondary binding posts 63 of the transformer Gwith the ends of electrodes F. Binding posts 63 extend through aperture 64 formed in the upper surface .of conduit D.

Electrodes F consist of elongated bars 65 surrounded at their rearward ends by cylindrical insulators 6]. The insulators are preferably composed of an electrically non-conductive material, such as silimanite, and are positioned by means of pinched protrusions or nibs 8'9, protruding from bars 65 and against which are placed positioning washers ll. Protrusions 69 prevent insulators 81 or washers 1| from traveling outwardly on bars 65. Each insulator 61 is prevented from traveling inwardly on bar 85 at its other end by means of connecting nuts 68 threaded onto each bar.

Press-flttedly inserted into the outer end of each bar 65 is an electrode tip 13, which is bent at a point approximately half way of its length, so that it will be properly positioned with respect to oil nozzle E. Electrode tips 13 are made of a highly heat-resistant material which is relatively expensive with respect to the material of which bars 65 are made. Inasmuch as those portions of the electrodes which extend to the rear of the nozzle are not subjected to high temperatures,it is not necessary that this expensive material be used throughout the length of bars 65. Consequently, a less expensive material, which, however, is a good electrical conductor, is used for elongated bars viii.

Substantially midway of the length of conduit D is a positioning or supporting device Tl, which is designed so that nozzle E and electrode tips '73, which are supported thereby, may be adjusted independently or collectivelyas desired. This device consists of standard 'l'l having a base I9 shaped to fit the interior of conduit D and provided with a threaded aperture 8| for the insertion of a clamping bolt 83. Bolt 83 extends through a slot 85 provided therefor in the bottom of the nosing and when tightened pulls base arouses "it into engagement with conduit D. Slot 86 permits limited longitudinal travel of the standard ll with respect to conduit D when mu til is loosened, thereby making it possible to move it into a plurality of adjusted positions. A central upstanding web tl connects base it of standard it with a longitudinal cylindrical portion at. cylindrical portion ts has a central aperture therethrough for the insertion of oil pipe til. There is also a vertical-threaded aperture through the cylindrical portion which connects with the central aperture for the insertion of a set screw it which is adapted to hold oil pipe it upon standard ill in various adjusted positions.

Located outwardly and upwardly from cylindrical portion 39 of standard ill, and connected thereto by means of a pair of webs 93, are two identical cylindrical portions. til, having ears ill on their outer sides. Ears W are provided w th horizontal slits 9t and vertical apertures iti. the latter being threaded in the portions located on the underside of slits. t9. Cylindrical portions 95 are provided with central apertures for the insertion of insulators M. are adjustably clamped or positioned-therein by means of clamping screws W3. threadedly inserted in apertures lill. When tightened. screws I03 cause the separated portions of ears 91 to be forced together.

From the above description it is evident that the nozzle E and electrode tips l3 may be adjusted with respect to each other. by manipulating them longitudinally of the conduit after loosening their clamping screws, and that the nozzle and electrode tips, may be collectively adjusted with respect to the conduit by loosening screw 83 and moving the entire assembly longitudinally of conduit D.

Inserted into the outer end of conduit D is an air-swirling device Hi1. This device has an inner cylindrical portion' I09 which is adapted to fit snugly into the inside end portion of conduit D and be heldth'erein by means of set screw III. A shoulder H3 is provided adjacent cylindrical portion 009 which limits .the distance air-swirling device I01 may be inserted into conduit D. The

outer portion of swirling device i0! is substan duit D without'departing from the spirit of the present invention.

Positioned on oil tube 49, and held in place by Yu set screw H9 is an air deflecting device i2i,

consisting of a metal inner member I25 and an outer member I29 of insulating material, such as dielectric porcelain. Inner member E23 is substantially cylindrical in shape, having a central aperture therethrough for the insertion of oil tube 49, and an outer surface of two sizes. The larger and rearmost portion has a threaded aperture. connecting the outer surface with the central aperture for the insertion of set. screw H9. It is by means of this set screw that the air deflecting device may be held in various longitudinally adjusted positions with respect to oil tube ts for securing the proper air-swirlingaction in the particular installation involved.

The insulators The larger portion changes abruptly to smaller portion its, thus forming shoulder it'll.

Outer member its, or the air deflector proper,

consists essentially of a hub portion its and a conical portion idl. Hub portion its is adapted to fit around portion lid of inner member M3 and abut shoulder ill. Outer member E28 is rigidly secured to inner member lit by means of porcelain cement iti, or any other suitable securing means, which is inserted between portion tilt of inner member B23 and inner diameter lid of hub portion 13b of outer member I29. Conical portion itl is provided with two longitudinally directed holes its through which electrodes F loosely project. As outer member in is made of an insulative material it is incapable of short-oircuiting the electrodes, which lie al- 'most in contact with the walls of holes ass.

" causes the helical air currents set up by blades the burner is to be used. There is no novelty claimed for the nozzle perse, as any atomizing nozzle having the desired characteristics and dimensions may be used. The electrode tips 13 are so adjusted that their terminals will be outside" of the main spray of liquid fuel ejected from nozzle E. This adjustment will be determined by whether a wide spray or a narrow spray nozzle is used. Were the electrode tips 13 directly in the main fuel spray they would quickly collect carbonand ignition would be impaired.

Regardless of how well the nozzle may be made,. there is always a fine spray'of fuel outside of,

and surrounding the main conical spray, in which the spark is located. It is, this fine spray which is first ignited. Baille i2i protects the spark from the direct blast of air and establishes at The operation of the burner is exceedingly simple. A suitable source of current is supplied whereby operation of the motor A is started which in turn turns the -fan B and the oil pump (2. Oil is pumped to the nozzle E and air is blown through the conduit D and forced by means of air deflector I20 through blades H5.

Current is also supplied to the transformer G and causes a spark to jump between electrode tips l3. Ignition of the truant oil from the main oil spray occurs and the flame spreads to the main spray, and the flame is carried outwardly from the burner nose, because of the velocity of the air supplied by the fan B. When the burner has come up to operating temperatures the ignition device is automatically shut oh by opening the primary circuit of the transformer, and this may be effected by" any suitable mechanism contained in the burner control.

Inasmuch as only the air-swirling device I01 and the very tip of conduit D projects into the combustion chamber the remainder of the mechanism is quite far removedfrom heat. Also, any heat imparted'thereto will be prevented from being conducted through the metal of conduit D back to the motor and other parts due to the cooling effect of the air blowing through the nosing in the opposite direction; in fact, during operation ahuman hand may be laid upon conduit D without discomfort.

From the foregoing description, it. is evident that an extremely simple and compact liquid fuel burning device is obtained. Due to the various adjustments provided, adaptability of the device to various types and sizes of installations is obtained. Due to. the use of an air deflector and fins for imparting a swirling motion, the atomized fuel and the air are intimately mixed, thereby avoiding rich or -,leanspots' and a swirling fire is obtained, which has proven to be the most efficient variety. 7

Although we have .illustrated, and prefer to support the air-swirling device on the conduit, it

is to'be understood that if desired it may be supported on oil pipe 49, and the appended claims are intended to embrace our invention when it is embodied in this form. Moreover the electrode assembly may be supported on pipe 49 instead of standard 11, without in any way impairing the operation of the apparatus.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. "The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the

scope of the invention being indicated by the United States Letters Patent is: 7 1. In a liquid fuel burning apparatus, ,a conduit; means for causing a stream of air to traverse said conduit; air swirling means adjacent the discharge end of said conduit for imparting a swirling motion to said stream of air as it leaves said conduit; said air swirling means comprising a plurality of blades extending from the inner wall of said conduit inwardly toward, but terminatin'g considerably short of the center of said conduit, to provide a comparatively large substantially unobstructed central opening adjacent the discharge end, of said conduit; and an air deflecting member centrally located with respect to the longitudinal axis of said conduit and disposed adjacent said air swirling means for deflecting substantiallygthe entire stream of air through said air swirling blades and means, located adjacent the discharge end of said conduit, for projecting a substantially cone-shaped stream of atomized liquid fuel into the air stream issuing plurality of air swirling blades disposed in said conduit adjacent said nozzle and extending toward the center of 'said conduit, but terminating short thereof, andair deflecting means disposed in said conduit in the path of said air stream for shielding said spark forming means from the direct action of said air stream, to thereby maintain a semi-quiescent zone adjacent said spark, said air deflecting means also deflecting the central part of said'air stream from the central axis of said conduit and into said air swirling blades.

3. The liquid fuel burning apparatus described in claim 2, wherein said air deflecting means is mounted for adjustment toward and away from said spark forming means for adjustably varying the degree of quiescence adjacent said spark and for adjustably varying the quantity ofair that is deflected away from the axis into said air swirling blades.

4. In a liquid fuel burning apparatus, a substantially cylindrical conduit adapted to convey combustion air to a combustion chamber, a fuel pipe centrally disposed insaid conduit and having a nozzle at the end thereof for mechanically atomizing liquid fuel, said conduit being provided' adjacent its discharge end with a plurality of inwardly extending air swirling blades, the free ends of said blades terminating considerably short of the axis of said conduit to provide a comparatively large central opening, means for blowing combustion air through said conduit toward the discharge end thereof, and a deflecting device disposed within said conduit for causing substantially all of the air blown therethrough to enter and be acted uponby said air swirling blades, said air deflecting device comprising a member disposed in said conduit and mounted upon said fuel pipe and presenting a substantially conical face to the stream of air flowing through said conduit, said member having a maximum outside diameter substantially equal to that of the central opening provided by said air swirling blades.

5. In a liquid fuel burning apparatus, a substantially cylindrical conduit adapted to convey combustion air to a combustion chamber, said conduit being provided adjacent its discharge end with a plurality of inwardly extending air swirling blades, the free ends of said blades terminating considerably short of the axis of said conduit to provide a comparatively large central opening, means for blowing combustion air through said conduit toward the discharge end thereof, a fuel pipe disposed in said conduit and located substantially centrally with respect to ply pipe for sliding movement toward and away.

from said nozzle? said air deflecting device having a pair of openings extending therethrough in a pipe and presenting a substantially conical face to the stream of air blown through the conduit,

direction substantially parallel to said fuel supply said air deflecting device having a maximum outmamas side diameter substantially mm m that of the central opening provided by sam air swirlflng blades, 2 pair of electrodes msmsed in said mm. duit and extending through said @pemngs in mid air deflecting device and terminating aqua cent said nozzle in a. pair of spam farming harms,

mendemtly of said air deflecting memmr, whereby the latter may be moved toward and away from said mmfiie witshwt dflsturbmg the pzasitiun 0i said eele fnmfies.

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